Calculating machine



3 A. A. HORTON CALCULATING MACHINE 4 Sheet-Sheet 1 Filed Aug. 12, 1927 0a. 20, 1931. A A HORTQN 1,827,890

CALCULATING MACHINE Filed Aug. 12, 1927 4 Sheets-Sheet 2 INVENTOR ATTORNEYJ Oct. 20, 1931. 'A. A. HORTON CALCULATING MACHINE Fil ed Aug. 12, 1927 4 Sheets-Sheet 5 aw 455332;; Jfl/ZM vim/ 4,

1931- A. A. HORTON CALCULAT ING MACHINE 4 Shets-Sheet 4 Filed Aug. 12, 1927 Patented Get. 20, i931 I UNITED STATES PATENT OFFICE ALLEN A. HORTQN, OF PLYMOUTH, MICHIGAN, ASSIGNOR TO BURROUGHS ADDING MACHINE COMPANY, OF DETROIT, MICHIGAN A CORPORATION OF MICHIGAN CALCULATING MACHINE Application filed August 12, 1927. Serial No. 212,373.

This invention relates to improvement in calculating machines.

It relates particularly to improvements in the type of machine that ordinarily requires a spacing stroke prior to taking a total and itconcerns a construction in which the necessity for taking a spacing stroke is eliminated. The invention is shown in connection with a Burroughs machine although not necessarily limited in its use to such a machine.

The well-known Burroughs type of ma chine has a series of actuator racks which descend to differential positions determined by key stops and which are returnedto normal in the return stroke of the machine handle.

To perform addition, a counter is rocked into engagement with the racks prior to their ascent and the pinions of this counter are rotated amounts corresponding to the differential positions of the racks. When one of the counter pinions rotates from its 9 to its 0 position it trips a pawl that controls the upper limit of movement of the rack of next high er order. When this pawl is tripped it is latched in tripped position with the re-,

sult, when the racks ascend, the rack engaging the pinion of next highest order moves an extra step of movement to move its pinion one step to effect a carry. In taking a total,

the counter is moved into engagement with the racks prior to their descent and thepositions of the racks are determined by the counter whose pinions are rotated by the racks to zero position where they are stopped by the engagement of transfer projections on them with feet on the pawls above mentioned. It will be obvious that, if some of the racks have been given an extra step of movement in the last operation preceding a total and, if while they are in this condition, the counter is moved into engagement with them to take a total, the total will not be correct because the racks do not occupy a uniform position at the start of the movement. Also, if any of the carry pawls are latched in tripped position their feet will be out of the paths of the transfer projections on their pinions and hence the pinions will not stop theirracks when the latter descend and another sources of error is introduced.

necessity for this spacing stroke slows up the operation of the machine to some extent and the present invention has been devised to per mit the taking of a correct total without the necessity for this stroke.

The object of the invention is to provide an improved mechanism for enabling a total to be taken on a machine of the type in which 7 the actuator racks are given an extra step of movement to effect the carry without requiring that the machine be given a spacing stroke prior to said operation.

Other objects and advantages of the invention will appear from the following specification and drawings.

An embodiment of the invention is shown in the accompanying drawings in which:-

Figure l is a skeleton left side elevation of a machine embodying the invention, the parts being shown in normal position and with some of them broken away to show others and to avoid confusion.

Fig. 2 is a fragmentary detail view of som of the sub-total key connections;

Fig. 3 is an enlarged skeleton view of the left side elevation'showing the positions of the parts with the total key depressed and with a transfer in the machine but prior to the handle being inoved forward;

Fig. 4 is a view similar to Fig. 3 with the total key depressed showing the positions of the parts when the handle has been moved forward to engage the counter pinions with the actuator racks. In this View the actuator racks have been restored to normal and the transfer mechanism has been returned part way to normal Fig. 4 is a detail view of an alternative construction of the rear end of one of the links shown in Fig. 4;

Fig. 5 is a perspective view of the total taking connections shown in side elevation in Figs. 3 and 4 looking at the same from the inside of the machine;

Fig. 6 is a perspective viewof one of the transfer latches which differs slightly in construction from the latch usually employed on the Burroughs machine;

Figs. 7,8, 9 and 10 are diagrammatic views showing the different positions the carry pawls occupy during a totaling operation.

The invention is shown applied to a standard Burroughs adding machine but it is to be understood that it may also be used with other machines operating upon the same general principles. The Burroughs construction is so well known that it will be described only briefly, reference being made to the many patents of the prior art which show its construction in detail.

The machine has a plurality of toothed actuator racks 610 carried on the ends of pivoted arms 611, whose other ends carry type bars 618. A pin and slot connection between the actuator racks and the arms permits the racks to have a one-tooth step of movement relative to the arms. The racks are normally urged upwardly to the limit of their movement by springs 680, the relative position of the parts under the influence of the springs being shown in Fig. 1. Each rack is normally held up by a latch 415 of which there is one for each bank of amount keys. The latch for a particular bank is released by depression of any one of the amount keys of that bank which moves a slide 214 rearward, said slide having an upwardly extending projection on its forward end for engaging the latch 415 of its bank. The arms 611 are normally held upwardly by abail (not shown) carried by the arms 613, one of which is shown in Figs. 1, 2 and 3. When the handle of the machine is pulled forward the bail is lowered which permits the arms 611 and their racks 610 to move, downwardly to extents determined by stops ositioned by amount keys on the machine. 11 the return stroke of the handle the bail is moved upwardly and it restores such of the arms 611 with their racks 610 as have moved downwardly. Under normal conditions when no carry takes place, the upward movement of the racks 610 is limited by the engagement of a stud 651 on each rack with a pivoted pawl 413 as shown in Fig. 1.' When the studs 651 strike their pawls 413, the arms 611 continue their upward movement one step against the tension of springs 680 which movement is determined by the pin and slotconnection between the arms and the racks.

The pawls 413 have downwardly extending arms provided with feet 413 which are engaged by transfer projections 920 on the pinions 916 of the counter. When one of the pinions 916 is rotated from its 9 to 0 position while in engagement with the racks during the ascent of the latter, and which occurs during a clockwise rotation of the pinion as viewed in Fig. 1, the pawl 413 which controls the actuator rack for the pinion of next higher order is moved rearwardlv to the dotted line position shown in Fig. 3 so that when the rack for the pinion of next higher order reaches its upper position its stud 651 is not engaged by its pawl 413 and the rack is thereby permitted to move an extra step to the dotted line position of Fig. 3. This advances the counter inio-n of next higher order one step and e ects a carry. When the pawl 413 is moved rearwardly it is latched in this position by the latch 411 which moves over the top of it under the influence of a spring 480 as illustrated in ig. 3. The pawl 413 is thus latched in retracted osition as soon as it is moved to this position by the transfer projection of the pinion controlling it.

The counter 916 is mounted on a rockable counter frame 910 which is rocked by means of a pitman 914 pivoted to an oscillating member 913 which, in turn, is actuated by a passby pawl 821 carried on the end of an arm 813 that is oscillated at each operation of the machine. In adding operations, the counter is moved out of engagement with the racks prior to their descent and is then rocked into engagement with them at the beginning of the return stroke and prior to their ascent so that the differential movement of the racks will be transferred to the counter pinions during the return movement of the racks. The manner in which the counter is thus rocked into and out of engagement with the racks will be clear by referring to Fig. 1. As the handle of the machine is moved forwardly the oscillating arm 813 is rocked counterclockwise which causes the pass-by pawl 821' to engage a stud 961 on the member 913 thereby rocking the latter counter-clockwise. This moves the pitman 914 forwardly and, since the pitman is in engagement with the upper portion of the counter-frame 910, the counter is rocked clockwise out of engagement with the racks. As the handle reaches the end of its forward stroke the pass-by pawl 821 passes the left hand stud 961 on the member 913 and at the beginning of the return stroke of the handle the pawl 821 engages the stud 961 and rocks the member 913 clockwise to pull the pitman 914 rearwardly to move the counter into engagement with the racks.

' During the ascent of the racks in an addition operation' the carrvs take place and consequently, at the end of an adding operation, some of the actuator racks have been advanced one step while others occupy their normal osition. The pawls 413 of the carried rac s are latched in tripped position while the others occupy-their normal positions.

When a total is to be taken the counter is not rocked out of engagement with the racks at the beginning of the forward stroke but is allowed to remain in enga ement with them. This is normally accomp ished by depression of the total key and operation of the machine which, through the medium of the link 911 moves the pitman 914 down wardly so that its upper branch is disengaged from the stud on the counter frame and its lower branch is in position to engage the stud 958 on the counter-frame after the pitman has moved forward. Accordingly, when the pitman 914 is moved forwardly at the beginning of the forward stroke of the handle, it simply moves forward so that its lower branch will engage over the stud 958. When the total key is depressed the bell crank lever 227 connected to it is rocked clockwise and a link 216 is moved rearwardly. This link carries a bail 209 which is moved rearwardly and which engages the tail ends of all the latches 415 to move them rearwardly to release all the actuator racks. The result is that when the total key is depressed all the actuator racks are free to descend but their descent is prevented by the bail carried by the arms 613 until this bail is moved by operation of the handle of the machine.

When the racks 610 descend in taking a total they move downwardly until they are stopped by the stopping of their respective counter pinions 916 which are rotated in a counter c ockwise direction until their ransfer projection 920 strikes the feet 413 of the awls 413 as illustrated in Figure 1. It will e obvious that if any of the pawls 413 were in tripped position during the taking of the total. the pinions corresponding to said pawls would not be limited in their rotation because the feet of the pawls would be out of the path of the transfer projections 920 of their pinions. This would result in an error, and, in addition, there would be an error if any of the racks 610 occupied their advanced positions at the time the counter was moved into engagement with the actuator racks. It is accordingly necessary in taking a total to restore the racks 610 and the pawls 413 to their normal positions. This is done by a spacing stroke in the standard Burroughs machine and this spacing stroke is compelled by looking the total key against depression until after a spacing stroke has been taken. This locking of the total key is accomplished by the tripped latches 411 which ordinarily have shoulders on them as shown, for example, in Vincent 897,941, that engage and move nearward a bail 423 carried by arms 424, the left hand arm being illustrated in Fig. 1. As the bail moves rearward, the u per end of the left hand arm 424 is move under a semicircular stud 425 on the bell crank lever 227 thus blocking the total key. The trip ed latches 411 are restored by means of a ail 930 carried by the pivoted arm 922 connected to a link 918 having a slot in its lower end eng 'ng over a stud 918" on the oscillating mem r 813 (Figure At the beginning 0 the forward spacing stroke of the handle, the counter is rocked out of engagement with the actuator racks and the bail 613 moves downwardly to release the arms 611 which thereby tend to drop but their movement is limited by the racks 610 which are held against movement by the pawls 415. Any of the racks that are up one step beyond normal position drop down to their normal position where they are caught by the pawls 415. As the handle reaches the end of its forward stroke the stud 918 on the arm 813 engages the left-hand end of the slot in the member 918 and rocks the arm 922 to move the bail 930 against the rearwardly extending portion of the pawls or latches 411. This moves the latches outwardly and permits the pawls 413 to be swung back to normal position by the springs 480 which normally urge them in this direction. This puts the pawls 413 in normal position and, since all of the racks have already movedto normal position. the parts are in condition for the taking of a total, the lock 424 for the total kev having been released in the standard machine under such conditions.

The present invention concerns improvements whereby the pawls 413 and the racks 610 may be returned to normal without the necessity for a spacing stroke.

Mechanism for eliminating spacing stroke Inasmuch as the counter is normally in engagement with the actuator racks at the end of an addition operation and remains in engagement during an ordinary totaling operation, the first thing necessary in order to permit the racks 610 to be returned to normal is to disengage the counter from the racks. This is accomplished in the present invention by depression of the total key as follows:

Connected to the bell crank lever 227 operated by the total key is a link which, in turn. is wnnected to an arm 21 fixed on a shaft 22 that also carries a two-armed lever 23 whose arm 24 is connected to a link 25 extending downwardly and having its lower end connected to a link 26 which is pivotally connected to the counter-frame 910 below the pivot of said frame. The link 26 carries a pivoted cam pawl 27 normally urged counterclockwise by a spring 28 into engagement with a stud 29 as shown in Fig. 5.

When the total key is depressed from the position of Fig. 1 to that of'Fig. 3, the bell crank lever 227 is rocked clockwise which causes a counter-clockwise movement of shaft 22 that results in thrusting the links 25 and 26 downwardly. Downward movement of the link 26 causes the cam edge of the pawl 27 to engage a stationary machine stud which cams the link 26 rearwardly and pulls the counter-frame 910 clockwise to rock the counter out of engagement with the actuator racks. In this way, depression of the total key results in rocking the counter out of enwhich normally move the bail 423 that acts to lock the total key. By referring to Fig. 6,

it will be observed tha v the latches 411 are devoid of these shoulders and hence when they are moved rearwardly during a. carry they do not engage bail 423 and no locking of the total key is eifected.

The racks 610 are released from the latches 415 by depression of the total key and they are freed for downward movement by the retraction of the bail 613 by operation of the machine. Ordinarily, at the beginning of the forward stroke in the taking of a total, the counter remains in engagement with the racks. Thisis due to the fact that depression of the total key moves the pitman 914 downwardly so that its lower branch is moved to a position on top of the stud 958 on the lower part of the counter-frame. If, however, the counter is out of engagement with the racks when the pitman is moved downwardly, the lower branch of the pitman engages over the stud 958. Assuming the parts to be in this condition, then, at the beginning of the forward stroke of the handle, the pass-by pawl 821 carried by the oscillating arm 813 normally engages a stud on the member 913 to move the pitman 914 forwardly and this would immediately rock the counter into engagement with theracks if it were out of engagement. If this were permitted to occur in the present machine the counter would be immediately rocked.into engagement with the racks even thou h it had been first moved out by depression 0 the total key. To avoid this, a construction is provided for changing the time of rocking the counter into enga ement with the actuator racks so that it is not moved into engagement until there has been an opportunity for the carried racks to return to normal. This mechanism is as follows The right hand stud 961 on the member 913 is ordinarily fixed to said member but, in the present construction, this stud is mounted on the end of a pivoted arm 40 that is normally urged counter-clockwise by a spring 41. It is prevented from moving counter clockwise by one arm 42 of a bell crank lever whose other arm 43 is connected to a link 44 which, in turn, is connected to the second arm 45 of the two-armed lever 23. When the total key is depressed the arm 45 is rocked counter-clockwise which results in movin the arm 42 upwardly out of the path of t e stud 961 so that the spring 41' may move the arm 40 counter-clockwise and thus change the position of the stud 961 relative to the pass-by pawl 821. The result is that when the arm 813 starts to move the pass-by pawl 821 does not immediately contact the stud 961 but moves through a limited distance before engagin the stud to rock the member 913. The roc ing of the counter into engagement with the racks is thus delayed momentarily.

It will be noted that the total key erforms two new functions when depresse (1) it moves the counter out of engagement with the racks, and (2) it times the mechanism for rocking the counter into engagement with the racks.

0) Restoring carry pawls It is necessary to restore the latches 411 to normal so that the tripped carry pawls 413 can move to normal in the paths of the transfer projections 920 on the counter pinions and this is also accomplished by depression of the total key.

Depression of the total key rocks the bell crank lever 227 clockwise which moves links 216 and 216 rearward. The link 216 has a stud 46 projecting laterally from it near its rear end and this stud operates in a slot in an angular link 47 whose lower end is connected to the lower end of a pivoted arm 922 carrying a bail 930. Accordin 1y, when the total key is depressed, the li 216 moves rearwardly which results in moving the link 47 rearwardly and rocking the bail 930 for ward. The bail 930 engages the end of the trip ed latches 411 and moves them counterclockwise toward their normal positions.

When a short slot is provided in the end of the link 47, as shown in Fig. 4, the bail 930 is rocked far enough forward to entirely restore the latches 411 and the entire restoration is accomplished by depression of the total key. 1

When a longer slot is employed, as shown in Figs. 1, 2, 3, and 4, the latches 411 are only partially restored, the final restoration being accomplished by operation of the machine during the final part of the forward stroke which causes the stud 918 on the arm 813 to the counter to move to engaged position as shown in Fig. 9, and it will be observed that with the parts in this position, the pawl 413 is in the path of the transfer projection on the counter pinion so that the pinion will be stopped in its zero position. The last position of the parts is shown in Fig. 10 where operation of the machine has completely restored the latch 411 to permit the pawl 413 to be moved by the spring 480 to normal position:

(b) Restoring actuator racks to normal When the total key is depressed and the link 216 moves rearwardly the bail 209 carried by the end of the link 216 of which there is one on each side of the machine is moved rearwardly against the tails of the latches 415 which are thereby-rocked counter-clockwise to release all the actuator racks. As the handle starts to move forward the arms 613 carrying their bail move downwardly to release the arms 611, which then start downward. The immediate action is to carry downward the racks 610 which have been given an extra step of upward movement in effecting a carry in the prior operation. This is due to the fact that the bottoms of the slots in these racks are in'contact with the pins on their arms 611 so that when the arms begin to move these racks are immediately moved downward. On the other hand, the racks which have not moved an extra step are not moved downwardly immediately because the pins on'their arms 611 are at tops of the slots in these racks and the arms 611 may move downwardly one step before the racks 610 are moved. The result is that the racks which have been given an extra step of movement are brought back to normal prior to picking up the racks that were in normal position.

pawl 821 engages the stud 9 1 and rocks the counter into engagement with the racks before they descend.

Tomm operation When the total key is depressed, the counter is rocked out of engagement with the actuator racks through the medium of the links 25 and 26 and cam plate 27 as previously explained and the arm 42 is moved upwardly to release the arm 40 so that the position of the forward stud 961 is changed to change the timing of the movement of theccounter into engagement with the racks. Depression of the total key also moves the link 216 rearwardly which releases the latches 415 to thereby release all the racks 610 and, at the same time, it either completely restores thelatches 411 which may have moved to latching position owing to the tripping of their pawls 413, or it restores them far enough to release the pawls 413 so that said pawls may move After the tripped racks have been returned to normal, the. pass-by the paths of the transfer projections awls to move. As the handle starts to move orwardly, the arms 611 start to move downward and the racks which have had an extra step of movement first move down to the same relative position as the other racks which frees the pawls 413 for movement to normal. Immediately after this occurs, the pass-by pawl 821 engages the forward stud 96land rocks the counter into engagement with the racks.

The racks thus occupy the same relative position when the counter moves into engagement with them, all the tripped carry pawls have been returned into the paths of the transfer projections 920 to act as stops for the counter pinions, and there is no necessity for a spacing stroke.

Sub-total operation The operation of the mechanism in taking a sub-total is much the same as in taking the total. Depression of the sub-total key rocks the bell crank lever 227' clockwise, which, through the medium of the link 50. moves the bell crank lever 227 clockwise which results in the same operation of the mechanism as if the total key had been depressed. The difference in operation is that one arm of the bell crank lever 227' is connected to one end of a pivoted member 51, which, when the bell crank lever is rocked by depression-of Restoring machine to condition for addition It is possible that an operator might depress a total or sub-total key and thus rock the counter out of engagement with the racks 610 after which he would change his mind before starting to pull the handle forward and decide to'add another item into the machine. In such event, it is desirable to have the parts returned to their original position and provision is made for accomplishing this result.

When either the total or the sub-total key is released the spring 52 which normally urges these keys toward their undepressed position. is strong enough to return the en tire mechanism actuated by these keys to its normal position. This results in raising the link 25 and the cam faced end of the link 26 comes in contact with a stud 53 on the arm end of the link 26 comes in contact with it, the link is cammed forward to rock the counter-frame 910 to move the counter into engagement with the racks. At the same time the link 20 connected to the bell crank lever 227 is moved forwardly and this results in moving the arm 42 downwardly so that its end cams the stud 961 back to normal position. The link 216 connected to the bell crank 227 is moved forward again which allows the latches 415 to drop back to latching position. The stud 46 on the rear end of the link 216* also moves the link 47 forward to return the bail 930 to normal position.

The parts operated by the total and subtotal key are returned to normal position in the same way after a totaling or sub-totaling operation. When either the total or subtotal key is depressed and the machine operated, the key is held down during the operation of the machine but, at the end of the operation, the key is released whereupon it is returned to normal as above described and the parts moved by it are likewise returned to normal.

It is to be understood that the structure shown is for purposes of illustration only and that variations may be made in it without departing from the spirit and scope of the invention as defined by the appended claims.

I claim:

1. The combination in a calculating machine having actuator racks that are iven an extra step of movement in effecting a carry, carry pawls having latches'that hold said pawls in tripped position when they are moved to effect a carry, a counter, means for moving the counter into and out of engagement with the racks, a total key having connections for causing the counter to be engaged with the racks at the beginning of operation of the machine in taking a total, and means operated by the total key for moving the counter out of engagement with the racks and for returning the tripped latches to normal; of means for'changing the timing of the movement of the counter into engagement with the racks by operation of the machine in taking a total, whereby the actuator racks that have moved an extra step and the tripped carry la ches and pawls are returned to normal before the counter is rocked into engagement with'the racks.

2. The combination in a calculating machine having actuator'racks that are given an extra step of movement in effecting a carry. carry pawls having latches that hold said pawls in tripped position when they are,

moved to effect a carry, a counter, meansfor moving the counter into and out of engagement with' the racks. a total key having connections for causing the counter to be engaged with the racks at the beginning of operation of the machine in taking a total. means operated by depression of the total key for moving the counter out of engagement with the racks, and means operated by depression of said total key for restorin the tripped latches; of means operated by epression of said total key for delaying the action of the counter moving means in moving the counter into engagement with the racks until the racks that moving the counter into and out of engagement with the racks, 'a total key having connections for causing the counter to be engaged with the racksat the beginning of operation of the machine in taking a total,"

means operated by depression of the total key for moving the counter out of engagement wih the racks, and means operated by depression of said total key for restoring the tripped latches; of means operated by depression of said total key for delaying the.

action of the counter moving means in moving the counter into engagement with the racks until the racks that occupy extra-step position have been returned to normal, and means for returning the counter into engagement with the racks and for restoring the counter moving means to normal when the total key is released without operating the machine.

4. The combination in a calculating machine having actuator racks, a counter, a total key, and means for rocking the counter into engagement with the actuator racks including a stud engaged by a pass-b awl at the beginning of the operation 0 t 0 machine; of means operated by depression of the total key for chan 'ng the time of the engagement of the pamy pawl with the stud as the machine is operated.

5. The combination in a calculating machine having actuator racks, a counter, means for rocking the counter into engagement with the actuator racks including a stud engaged by a pass-by pawl as said pawl moves in a given direction, and a total key; of means operated by depression of the total key for changing the position of the stud to vary the time of engagement of it by the pass-by pawl as said pawl is moving in said direction.

6. The combination in a calculating machine having actuator racks, a counter, means for rocking the counter into engagement with the actuator racks including a stud engaged by a pass-by pawl, and a total key; ofa

pivoted arm carrying said. stud and having a limited path of movement, a spring urging said arm in one direction, a latch normall holding said arm'against movement, and con- I nections operated by depressionof the total kevforreleasing-said latch.

7. The combination 1n acalculating machine having actuator racks, a counter normally in engagement with said racks, and a total key; of mechanism actuated by depression of said total key for rocking said counter out of engagement with said actuator racks, meansfor returning said mechanism to normal when said total key is released prior to operation of the machine, and means forcausing said mechanism, when so returned to ment with saidactuator racks.

8. The combination in a calculating machine having actuator racks, a counter nor-'' mally in engagement with said racks. and a total key; of mechanism operated by said total'key including a cam device acting to move said counter out of engagement with normal, to move said counter into engagei said racks when the total key is depressed,

means for returning said mechanism to nor.- mal when the total key is releasedprior to operation of the machine, and a second cam means for causing said mechanism, when so released. to move said counter into engage ment with said actuator racks. Y

' In testimony whereof I have subscribed my name.

ALLEN A. HORTON. 

